In the practice of diagnostic medicine, it is often necessary or desirable to perform a biopsy, or to sample selected tissue from a living patient for medical evaluation. Cytological and histological studies of the biopsy sample can then be performed as an aid to the diagnosis and treatment of disease. Biopsies can be useful in diagnosing and treating various forms of cancer, as well as other diseases in which a localized area of affected tissue can be identified.
Biopsies are routinely performed on tissue using a needle set. One known needle set includes an outer cannula having a pointed tip and a tissue receiving opening defined near its distal end, and an inner cannula having an open distal end surrounded by an annular cutting blade. The inner cannula is slidably disposed within the outer cannula so that it can close the tissue receiving opening, thereby cutting tissue prolapsing into the lumen of the outer cannula through the tissue receiving opening. Typically, a hub is connected to the proximal end of each needle. Such needle sets are used with or incorporated in various forms of biopsy devices, including motor driven biopsy devices.
Current motor driven biopsy devices present issues involving sterilization of the devices after use, which may lead to shorten device lifespan. Further, current biopsy devices are typically introduced into tissue with the tissue receiving opening in an open state, which increases drag during introduction into tissue.